Bacteria-resistant fabric



United States Patent 3,275,041 BACTERIA-RESISTANT FABRIC Beverly E. Williams, La Grange Park, 11]., assignor to Hodges Research and Development Company, New

York, N.Y., a corporation of California No Drawing. Filed Sept. 21, 1964, Ser. No. 398,087

12 Claims. (Cl. 139-424) The present invention relates to fabrics, and more particularly to fabrics for use Where a high degree of resistance to microorganisms is required.

In hopsitals and institutions and other places where sterile conditions are necessary, it is highly desirable to provide linen, including bed linen; table linen; towels; gowns; jackets, and other frocks for personnel; etc., which does not readily serve as a carrier for' germs and other infections organisms. Infection of institutionalized patients, especially by Staphylococcus organisms, presents a considerable problem in view of the resistance of such organisms to standard treatments. Attempts have been made to impart bacteriostatic properties to fabrics by impregnating the fabrics and/ or the yarns and fibers which I make up the fabric with a bacteriostatic agent, but such treatment is effective for only a limited number of washings and resterilizations. Sterilization treatments are also effective to reduce or inhibit the bacterial counts, but such treatments are normally not entirely effective against subsequent contamination.

The present invention provides a fabric which exhibits permanent antifungal and antibacterial properties without the need for special treatments and the like.

The invention provides a tightly woven, substantially lint-free fabric embodying long-staple highly-twisted yarn.

More specifically, the present invention provides a novel woven fabric suitable for use in institutional linen composed of ramie or ramie-like fibers twisted into yarns having at least ten turns per inch with a yarn count in the neighborhood of 20/ 1 and woven with both a warp count and a weft count of at least 40 per inch throughout the fabric.

These and other objects of the invention will be apparent from a consideration of the following specification and claims.

It is possible to produce a bacteria-resistant fabric by producing a fine-mesh or tight-weave, lint-free ramie fabric.- Ramie fabrics made in accordance with the invention have been found to severly restrict bacteriological growth and may, indeed, actually suppress such growth. The bacteria which have been proved to be controlled by the use of a fabric in accordance with the invention include Staphylococcus organisms which at the present time, are considered to be one of the most diflicult to control. Such fabric also retards the development of fungus and other germs. Thus, the invention has application not only to institutional linen, but also to clothing fabric which is normally subject to fungus attack, such for example as infectious athletes foot disease.

Ramie is a bast fiber which is possessed of certain characteristics which have been found highly advantageous in the production of fabric in accordance with the invention. Ramie yarn is strong, durable, absorbent and flexible, both when Wet and when dry. The fiber itself is relatively smooth and has a staple length in excess of two inches and averaging four inches. The individual cells of the ramie fiber are considerably longer than any other natural fiber, in some instances the cell ofthe fiber being coextensive in length with the staple length.

In accordance with the invention, the fabric embodies yarns made from ramie fiber, which are more highly twisted and finer than conventional ramie yarn. When twisted at least ten turns per inch, the ramie yarn exhibits lint-free characteristics. ance with the invention, the highly-twisted yarn should be made with rather fine yarn count, i.e., in excess of 13 and preferably in the neighborhood of 20/1; in other words, the yarn may be single ply and of a thickness such that twenty 840-yard skeins weight one pound. In such a yarn, the yarn weight is 16,800 yards per pound.

In accordance with the invention, the fabric is a finemesh with a count or yarn-density in the warp and fill directions in excess of 40 yarns per inch throughout the fabric. The fabric in accordance with the invention exhibits the properties necessary for use as institutional linen, in that it breathes, is absorbent, and has good tear and burst strength. As a mater of fact, ramie fabric has greater tear and burst strength'when wet than when dry.

Typical woven fabrics in accordance with the invention are shown in the following table:

Table Example A Example B Example 0 Example D Weave Pattern X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Weave- Plain Plain Twill Flat Duck Yarn Count (cotton system):

Filling 24/1 20. 3/1 18. 2/1 18. 4/1 Yarn Twist (turns/inch):

Warp 12.1 13. 8 15. 6 12. 9

Filling 15. 4 16. 5 14. 0 13. 5 Fabric Count (Yarns/ ch) Warp 74 54 76 62 Filling 61 48 55 Fabric Weight:

Ounces/yard 4. 91 4. 44 5. 72 7. 02 Grab Strength (dry-pounds):

Filling 103. 3 63. 9 106. 0 116. 5 Trapezoid, Tear Strength (dry-pounds):

Warp 11. 0 9. 9 16. 8 9.3 Filling 7. 6 7. 4 8.0 11. 3

For making a fabric in accord- The figures in the above table were derived from destructive analysis of a conditioned fabric using standard test procedures, and may vary somewhat from the weaving specifications. It was found that the grab strength increased over 15% when the fabric was wet, and the trapezoid tear stength increased over 40% when the fabricv in draw sheets, aprons, and the like.

The fabric of Example D is" comparable to cotton duck orcanvas in its usage. "A similar fabric, but of heavier weight, may be used in canvas shoes with good resistance to wear and excellent suppression of fungus microoragnisms.

Ramiefabrics in accordance with'the invention, in

comparison to the standard cotton fabrics, provide greater absorbency, comparable stain shedding, and increasing whiteness upon laundering, as well as the incomparable resistance to microorganisms. While it is preferred to use 100% ramie throughout, it may be found desirable to blend a minor proportion of synthetic fiber into the yarn so as to increase the crease-resistanceand to provide'certain wash and wear properties. Such synthetic fibers should preferably be of a staple length corresponding to the staple length of the ramie and the fibers should exhibit a smooth surface contour and resist linting so as to be comparable to the ramie fiber'in those properties which are effective to retard or suppress a 7 growth of microorganisms.

For specialized end uses, it may be desirable to subject the fabric to further treatment, such as singeing to insure removal of any lint, exposing the fabric to ultra violet or cobalt radiation to sterilize the fabric, passage of the fabric through an electrostatic .field to remove foreign particles which may support the growth of microorganisms, or other cleansing and/or sterilization treatments. For the majority of uses, however, such further treatment is unnecessary.

Modification is possible in the nature, construction, and weave of the yarns and fabrics as well as in the exact procedures and techniques employed in making the same without departing from the scope of the present invention, as defined in the following claims.

I claim:

1. A fine-mesh lint-free fabric exhibting high resistance to microorganisms comprising yarns of ramie fiber, said yarns being single ply yarns twisted at least 10 t.p.i. and

having a fine yarn count in excess of 13, the yarn density of said fabric in both directions being at least 40 .yarns per inch throughout said fabric.

2. A fabric according to claim 1 wherein all of the fibers in all of the yarns in the fabric have a staple length in excess of 2 inches, have a smooth contour, and resist linting.

3. A fabric according to claim 2 wherein said fabric is composed 100% of ramie single ply ramie yarns.

4. A fabric according to claim 1 wherein said fabric is woven sheeting, the warp yarns having a twist of approximately 12.1 t.p.i. and-a yarn count of approximately 20/1 and filling yarns having a twist of approximately 15.4 t.p.i. and a yarn count of approximately 24/ 1.

5. A fabric according to claim 1 wherein said fabric is woven, the warp and weft yarns having a twist in the range of 12.1 t.p.i. to 16.5 t.p.i.

6. A fabric according to claim l wherein said fabric is woven, the warp and weft yarns having a yarn count in the'range of 13.4/1 to 24.0/1.

7.'A fabric according to claim 1 whereinsaidfa'bric is a plain weave having a warp count in the range, of-54 to 74 and a filling count in the range of 48 to 61.

8.A fabric according to claim 1 wherein said fabric is a fiat duck Weave having a warp countiin therange of 62 and a filling count in the rangexof 55.

. 9. A fabric according to claim 1 wherein saidfabric is a twill weave having-a warp count in the range of 76 and a filling count in therange of 55.

10. A fabric according to claim 1 wherein said fabric is in a singed condition to remove any lint therefrom. 11. A fabric according to claim 1 therein said fabric is in sterilized condition by radiation treatment.

12. A fabric according to claim 1 wherein said fabric has a higher warp count than filling count.

References Cited by the Examiner UNITED. STATES PATENTS 1,256,657 2/ 1918 Cameron et a1. 2872 2,091,237 8/1937 Evan 139383 2,423,707, 7/1947 Kenyon et a1. 139-426 2,495,893 1/1950 Guerillot 28 --72 3,155,123. 11/1964 Williams 139-426 FOREIGN PATENTS 370,552 12/1906 France. 447,483 10/1912 France.

3,323 of 1900 Great Britain. 6,473 of 18 84 Great Britain. 28,184 of 1904 Great Britain. 476,966 12/1937 Great Britain. 733,041 7/ 1955 Great Britain.

OTHER REFERENCES Americas Fabrics, The Macmillan Co., New York 1947, C2, pp. 137-139.

Catalogue of Useful Fiber Plants of the World, Government Printing Office, Washington, D'.C., 1897, SB 241 U5, No. 9, C2, pp. -91.

Textile Industries, Processing Ramie on Mill'Equipment (reprint of an article), June 1960.

The Textile Manufacturer, Ramie: An Old Fibre With New Potentialities, April 1950, pp. 172, 173 and 193.

MERVIN STEIN, Primary Examiner.

DONALD, W. PARKER, Examiner.

J KEE CHI, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N05 3,275,041 September 27, 1966 Beverly En Williams It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 21, for "microoragnisms" read microorganisms line 52, for "exhibting" read exhibiting column 4, line 2, strike out "ramie", first occurrence,

Signed and sealed this 22nd day of August 1967c L) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. A FINE-MESH LINT-FREE FABRIC EXHIBTING HIGH RESISTANCE TO MICROORGANISMS COMPRISING YARNS OF RAMIE FIBER, SAID YARNS BEING SINGLE PLY YARNS TWISTED AT LEAST 10 T.P.I. AND HAVING A FINE YARN COUNT IN EXCESS OF 13, THE YARN DENSITY OF SAID FABRIC IN BOTH DIRECTIONS BEING AT LEAST 40 YARNS PER INCH THROUGHOUT SAID FABRIC. 